1. Field of the Invention
The present invention relates to an improved nozzle for use with in-mold coating processes.
2. Background Art
In-mold coating processes are used in a number of applications to spray, or otherwise apply, coatings onto the working surfaces of molds used in molding operations. One common application of in-mold coating can be found in the processes used for manufacturing the soft interior paneling of automotive vehicles, like the soft interior paneling of an instrument panel dashboard 10, shown in cross-section in FIG. 1. Instrument panel 10 can be manufactured by a skin making process or a foam-in-the-mold process that each include spraying a mold, like mold 12 shown in FIG. 2, with a coating such as a one or two component waterborne acrylic, or a one component or two component urethane, or other material. The material hardens to form a relatively thin covering 14, generally 0.80 to 1.20 millimeters, which is used as a finished coating for a final color and gloss for appearance and UV-resistance to sunlight. In the case of skin making, skin 14 is removed from mold 12 for application to foam material 16 at another location. The foam-in-the-mold process is similar to the skin making process, except foam material 16 is applied to the skin 14 by a foam injection device (not shown) while the skin is in mold 12, instead of at a different location like the skin making process.
Referring to FIG. 1, the skin 14 includes a curvilinear or arcuate rim portion 18 extending along the outer periphery of skin 14 for gripping foam material 16. To form curvilinear rim portion 18, or other edges and flats that bend away from the outer surface of the skin and roll back over towards the center of the skin, an undercut mold portion 20 is needed within mold 12, as shown in FIG. 2. The undercut mold portion 20 is a difficult-to-reach area for applying the coating. In the past, a collinear applicator 22 has been used to apply the coating to form skin 14. For example, the collinear applicator 22 is mounted to a robot 24 and moved around working surfaces 13 to spray coating onto mold 12. As shown in FIG. 3, mold opening 26 somewhat prevents direct viewing of undercut portion 20 from outside of mold 12. Accordingly, those areas in mold 12 which are not directly viewable from outside mold 12, like undercut portion 20, are difficult for collinear applicator 22 to squarely spray with the coating. Thus, such areas are considered difficult-to-reach areas of mold 12.
As it is difficult for collinear applicator 22 to reach the difficult-to-reach areas, additional measures are required to manufacture skin 14 with collinear applicator 22. For example, since collinear applicator 22 cannot squarely spray undercut portion 20 (in order to squarely spray a surface, the surface must be within a width of a fan spray pattern of the applicator), the methods which use collinear applicator 22 must either coat the uncoated areas in a secondary operation, which usually consists of a human operator using a spray gun, or coat around the uncoated areas with excessive amounts of coating material so that the material can run down the sides of mold 12 to the difficult-to-reach surfaces. It is expensive, however, to have operators coat the uncoated portions in a secondary operation, and it is similarly expensive to apply excess material to the mold. Moreover, the excess coating can cause additional problems in bi-color applications in which it is desirable to have one portion of the skin coated with a first color and another portion of the skin coated with a second different color, as the running of coating material from one color into the other color can discolor the appearance of the skin.